I got this as a freebie when I bought a stainless stove and OTR microwave out of a foreclosed home for $100. When I went to unhook it the wires and wire nut were melted and fried from over heating. Attached is a picture. I already remove the everything to see if something was jammed in the pump etc. but it was all clear and clean. What would cause this.

JUst finished installing it in my kitchen and it has a bad control board. Front panel started smoking real bad and now my house stinks. Lol! They dont sell the boards anymore from what I found on the net. I did see complaints about them catching fire though. Maybe this is why? Guess I have a parts machine.

I come across burnt wire nuts all the time also. The installer gets in a hurry & doesn't pre twist the wires before twisting the wire nuts. An very old master electrician taught me well 30 years ago to make the connection strong & tight before installing the wire nut on connection. The board more than like was damaged do to the wire nut connection arcing from the sloppy install & thus when re-energized went to smoke it self. My 2-cents.